Money isn’t the only green thing New Yorkers can associate with the Bank of America.

The bank’s crystalline tower going up at the corner of West 42nd Street and Sixth Avenue in Midtown will be the city’s greenest office building when it opens in 2008 – with energy-efficient heating and air conditioning, and pollution-reducing plumbing and drainage.

Amazing new technology makes being environmentally friendly very economical, said Douglas Durst, co-president of the Durst Organization, which is leading the $1.2 billion project.

“It’s slightly more expensive to build,” Durst said. “But if you build a better building and you are careful, these systems pay for themselves very quickly.” Many of the environmentally advanced features of the 945-foot, 64-story building – such as its reuse of rainwater and waste water in its toilets – required special variances from city building rules.

“It’s been easy to grant the variances, but it ended up being another step for them,” said Department of Buildings spokeswoman Jennifer Givner.

A revamping of New York’s building code now under way will make it easier for developers to construct environmentally friendly structures in the future, Givner said.

Many of Manhattan’s newest skyscrapers are environmentally efficient – the Hearst Tower on 57th Street and Eighth Avenue has coated glass designed to keep the sun’s heat at bay, and the Condé Nast building in Times Square, also built by the Dursts, has energyefficient air chillers.

But they’ll be topped by the Bank of America building’s features, which are expected to make it the first skyscraper to earn a “platinum” rating from the US Green Building Council.

* The building’s toilets will be flushed with rainwater drained from the roofs and wastewater filtered from the plumbing system.

* Urinals will be filled with an oil that is lighter than water. Urine will sink below the oil and be odorlessly flushed away without any water.

* Air conditioning vents will be on the floor instead of the ceiling. When cooled air is piped in through the ceiling, it has to be chilled at about 55 degrees. But when it comes from the floor, it only has to be 65 degrees.

* Floor-to-ceiling windows are being designed to let sunlight in while dissipating the sun’s heat.

* A cogeneration plant will produce electricity during the day and be used to make ice for the building cooling system over night.

* About 40 percent of the materials in the building are recycled – and about half of the construction material will come from within 500 miles of New York, saving on shipping costs.

Durst said the building’s environmentally-friendly features will make it a more comfortable place to work.

“All these things make the occupants a lot more productive,” he said. “You won’t feel at the end of the day like you are ready to take a nap.”